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David Stephens

Contributor

David Stephens is an “old school” z/OS systems geek. As the Lead Systems Programmer for consulting firm Longpela Expertise, he helps firms around the world with their z/OS related problems: from implementing Sysplex features to saving CPU. He started with mainframes in 1989, filling many different systems roles including seven years developing software for IBM.

David currently lives in Perth, Western Australia, and when his family lets him, will happily watch cricket for days.
 

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Articles

Six Defining Characteristics of z/OS and Mainframe

David Stephens

July 12, 2023

IBM Z mainframes and z/OS are important, still carrying out critical back-end processing after nearly six decades. But some things about mainframes seem strange. I mean, why the obsession with batch? And why do sites have so few z/OS systems? Let’s look at six characteristics of the mainframe and z/OS that help explain what it […]

Articles

Hashes and How to Create Them on z/OS

David Stephens

January 10, 2022

Hashes can be really handy. Want to confirm that a file was received intact? Compare sender and receiver hashes. Want to see if a file has been updated recently? Compare hashes generated over time. Want a fast key for a lookup table? Use a hash as the key. But what are hashes, and how can […]

Articles

5 Quick Ways to Speed up Your z/OS Batch Without Application Changes

David Stephens

October 28, 2021

z/OS users understand that batch is still important. However, with pressure to reduce downtime and offer 24-7 online services, it seems we always need to reduce our batch window. Or in other words, make our batch jobs run faster. The good news is that z/OS has a lot of features that may speed up batch, […]

Articles

Random and ‘Almost Random’ Numbers on z/OS

David Stephens

September 17, 2021

Random numbers can come in handy. They can be used to create a unique filename, generate a random new password, or randomly select a record. The good news is that we can obtain random numbers on z/OS. Well, at least some of them are random. COBOL and RANDOM A quick look at the IBM Enterprise […]

Articles

How to Use JSON in Your z/OS Program

David Stephens

July 7, 2021

First created in 2001, JavaScript Object Notation (JSON) has become the preferred way of creating structured data. Not limited to JavaScript applications, JSON formats can be found in web requests and responses and NoSQL databases. So, it makes sense that we will want our traditional z/OS programming languages (COBOL, PL/I, Assembler, C and REXX) to […]

Articles

Node.js on z/OS: How Real Is It?

David Stephens

May 24, 2021

Node.js is a popular environment to allow JavaScript to run outside of a browser. A 2020 Stack Overflow survey saw 50% vote Node.js as the most popular framework, library or tool. Anyone working with the open-source mainframe framework Zowe will be familiar with Node.js: it’s needed for both the Zowe server and Zowe CLI. But […]